As memory clock speeds continue to rise, clock signal reliability and accuracy have become increasingly important, particularly with respect to amplitude, frequency, and distortion. In many cases, a memory may operate using several clock signals. For example, a memory may operate in different modes using different frequency clock signals. In some instances, a memory may receive a global clock signal and internally derive various clock signals having different frequencies from the global clock signal.
In higher frequency memories, operation according to multiple frequency clock signals may require use of smaller set up and hold margins. Margins, however, must nonetheless be sufficiently large such that signals are properly captured. A known approach to minimize misalignment of clock signals is to provide each clock signal through a matching clock path. In this manner, clock signals may be better aligned. However, due to inherent variations in components of each clock path, some variation in clock alignment may persist, preventing further decrease in the margins and as a result preventing further increase in frequency while maintaining stable operation.